Collapsible ladder



April 21, 1964 H. A. KEITH COLLAPSIBLE LADDER Filed Feb. 11, 1963INVENTOR United States Patent 3,129,785 COLLAPSIBLE LADDER Herbert A.Keith, 64 Broolrdaie Ave, Toronto, Gntario, Canada Filed Feb. 11, 1963,Ser. No. 257,612 3 tilaims. (Cl. 18224) This invention relates toimprovements in collapsible ladders and more particularly toimprovements in a collapsible ladder which quickly adapts to suitdifferent applications.

A survey of the prior art reveals numerous structures generally designedto act either as a triangularly formed step ladder or as an extendedwall ladder. While certain of these devices achieve their severalintended objects with varying degrees of effectiveness, many still leavemuch to be desired both operationally and from a safety point of view.

It is therefore, a main object of the instant invention to provide acollapsible ladder which may be used as a triangularly formed stepladder or as an extended wall ladder.

It is another object of this invention to provide a collapsible ladderwhich, upon being used as a tri-angularly formed step ladder, presents aworking platform, such a platform being capable of positioning at theapex of the step ladder or at a lower elevation thereon according torequirements.

Still another object of this invention is to provide a collapsibleladder having a bracing section which acts as a rigid stabilizer in thetriangular step ladder and, in addition to bracing the ladder in itsextended form, acting as a runged section of the complete ladder.

Yet another object of the instant invention seeks to provide acollapsible ladder which is exceptionally safe in use.

A further object of the invention is to provide a collapsible ladderwhich is light, relatively inexpensive to manufacture, readily portableand rigidly braced during use thereof.

These and various other pertinent objects and features of my inventionwill become more readily apparent from the following detaileddescription and when taken in conjunction with the accompanyingdrawings, in which:

-FIG. 1 is a perspective view of a collapsible ladder embodying thisinvention mounted in the step ladder attitude and having its Workingplatform positioned at the apex thereof.

FIG. 1a is a plan view of the underside of the working platforms.

FIG. 2 is a perspective view of a collapsible ladder mounted in asimilar attitude to that illustrated in FIG. ,1 but having the workplatform in a lower position.

FIG. 3 is a perspective view of a collapsible ladder in its fullyextended attitude for use against a wall or the like.

Referring to FIGS. 1 and 2, a collapsible ladder indicated generally bythe arrow includes a first section 11 and a second section 12. Firstsection 11 includes two side rails 11a and 11b held in a parallel spacedapart relationship by a plurality of rungs 11c and elongate rectangularsteps 11d, rungs 11c and steps 11d extending perpendicularlytherebetween and in parallel spaced apart relationship to each other.

It will readily be understood that steps 11d are included so that auser, having to stand on collapsible ladder 10 for any length of time,may do so with more support and comfort to his feet than would be thecase if section 11 comprised the conventional circular sectioned rungsonly.

Second section 12 of collapsible ladder 10 includes Patented Apr. 21,1964 two side rails 12a and 12b held in a parallel spaced apartrelationship by a plurality of rungs 12c, rungs 12c extendingperpendicularly therebetween and in parallel spaced apart relationshipto each other. A top rung 12d is ofiset from the rest of rungs 12c andhas its respective ends housed Within two outwardly projecting sections13 formed on the edges of side rails 12a and 12b respectively, and across piece 14 of rectangular section is pivotally retained at the topof side rail 12a by a pivot pin -15 at one end thereof, its opposite endbeing received within a U hook 16 rigidly afiixed at the top of siderail 12b.

Sections 11 and 12 of collapsible ladder 11) are hingedly joined attheir upper ends by conventional hinge plates 17, hinge plates 17 beingmounted in such a manner as to permit sections 11 and 12 to be angularlylocated through 180 degrees.

Referring now to FIGS; 1, la and 2, two rectangular work platforms 18and 19 are hingedly attached at adjacent edges by conventional hingemeans 18a, platform 18 having its opposite edge pivotally retained uponthe uppermost run-g11c of section 11. Platform 19 has two parallelspaced apart lugs "19a rigidly affixed upon its underside andsubstantially toward its unhinged end;

Lugs 19a, which are adapted to project perpendicularly outwardly fromthe underside of platform 19, each have a rectangular cut out section 1%formed therein.

Referring now particularly to FIG. ;1 platforms 18 and 19 may be soadjusted to present platform 19 as a horizontally disposed workplatform, cut out sections 1% of lugs 1% receiving cross piece 14 andplatform 18 acting as a substantially vertical brace.

A third section 20 of collapsible ladder 10 includes two side rails 20aand 2% held in a parallel spaced apart relationship to each other.

Section 20 of collapsible ladder 10 has the upper end of side rails 20aand 20b pivotally retained upon that rung 12c of section 12 immediatelybelow offset rung 12d, side rails 20a and 29b being so spaced apart asto fit within the inner limits of side rails 12a and 12b and 11a and 11bof collapsible ladder 10, the opposite ends of side rails 20a and 20bterminating in hooked sections 20d and 20:2 respectively, hooks 20d and20a projecting longitudinally outwardly therefrom.

Still referring to FIG. 1, section 24) of collapsible ladder 10 has itstwo hooks 20d and 2lle located about the lower rung 11a of section 11thereby acting as a rigid stay between sections :11 and 12 andpreventing the two sections from further outward movement.

Referring now to FIG. 2, platforms 18 and 19 may be so adjusted as topresent platform 18 as a horizontally disposed work platform locatedsubstantially two thirds of the way up collapsible ladder 1b in thetriangularly formed attitude, the hinged end of platform 18 resting onthat rung immediately beneath offset rung 12d, platform 19 being locateddiagonally between said rung 12c and the rung 12c immediately below.

It will be readily apparent that platform 19 will, in this position,also pass diagonally between two of rungs 200 of third section 20 whichis located in longitudinal alignment within section 12, the hooked endsof side rails 20a and 20b being retained by spring loaded dowels 21similar to the type shown by U.S. Patent No. 2,901,054 at 46, locatedsubstantially toward the lower ends of side rails 12a and 12b andprojecting inwardly therefrom.

As section 11 has no further rungs above that rung 11c upon whichplatform 18 is pivoted, a user may stand or kneel Within sections 11 and12 of collapsible ladder 10. Also cross piece 14 may be swung clear ifso required.

Referring to FIGS. 2 and 3, upon collapsible ladder 10 having its twosections 11 and 12 opened outwardly to the full extent, the upper endsof their respective side rails 11a and 11b and 12a and 12b will abut,sections 11 and 12 forming one longitudinally disposed ladder for useagainst a wall or the like. Section has its hooked sections 2ild and 20aof side rails 20a and 2012 respectively affixed on top rung 11c ofsection 11 thereby providing rungs for the upper portion of section 11and completing the step sequence of extended collapsible ladder 10.

It will be appreciated that in order to affix hooks 20d and 202 inlocation about the top rung 200, said hook sections will have to bepositioned slightly below the rung, this being achieved with sections 11and 12 just short of longitudinal alignment, complete alignment liftinghooks 20d and Zfie into position about the rung.

A small outwardly projecting stop member 22 located at the top of siderail 11a and on its outward edge prevents cross piece 14 from swingingdownwardly about pivot pin 15.

Referring to FIGS. 1a and 3, in the extended position of collapsibleladder 10, platforms 18 and 19 are folded inwardly about hinge 18a, lugs19a affecting a friction fit upon two retainer dowels 18b, dowels 181)being located within recessed housing 180 of platform 18 andsubstantially toward the pivotal edge thereof, dowels 18b beingfrictionally received by cut out sections 1% of lugs 19a therebyallowing platforms l8 and 19 to achieve a face to face contact.

It will readily be seen that platform 18 may if required be detachablyhinged to top rung 11c of section 11, thereby allowing for removal uponcollapsible ladder 10 being assembled in the extended attitude, thisbeing a matter of individual preference.

The general design of the individual parts of the invention as explainedabove may be varied according to requirements in regards to manufactureand production thereof, while still remaining within the spirit andprinciple of the invention, without prejudicing the novelty thereof.

The embodiments of this invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A collapsible ladder comprising a first section, a second section, athird section, a first platform member and a second platform member;said first section and said second section being hingedly joined attheir upper ends; said first section includes two side rails held inparallel spaced apart relationship by a plurality of rungs andrectangular steps, said rungs and said steps extending transverselytherebetween and in parallel spaced apart relationship to each other;said side rails terminating in an upper section having neither rungs norsteps; said second section including two side rails held in parallelspaced apart relationship by a plurality of rungs, said rungs extendingtransversely therebetween and in parallel spaced apart relationship toeach other; a cross piece pivotally retained at one end thereof to theupper end edge of one of said side rails of said second section, theopposite end of said cross piece being located within a U hook, said Uhook being rigidly affixed on the upper end edge of the other of saidside rails of said second section, said cross piece being parallel withsaid plurality of rungs; said third section including two side railsheld in parallel spaced apart relationship by a plurality of rungs, saidrungs extending transversely therebetween and in parellel spaced apartrelationship to each other, said third section being substantiallyshorter than each of said first and second sections; said third sectionbeing pivotally retained at the upper ends of its said side rails uponan upper rung of said second section, the lower ends of said side railsterminating in hooked sections, said hooked sections projectinglongitudinally outwardly therefrom, said side rails of said thirdsection being so spaced apart as to fit within the inner limits of saidside rails of said first and said second sections; said hooked sectionsof said side rails of said third section being located about said lowerrung of said first section said first platform member and said secondplatform member hingedly joined at adjacent edges; said second platformhaving at least one lug, said lug being located on the underside thereofand projecting perpendicularly downwardly therefrom, said lug having acut out section formed therein, said cut out section receiving saidcross piece said first platform member having the edge opposite thehinged edge pivotally attached to an upper rung of said first section;said first platform depending angularly downwardly between said secondplatform and said upper rung of said first section; and said secondplatform being horizontally disposed.

2. A collapsible ladder as defined in claim 1 in which said first andsaid second sections form one longitudinally disposed ladder, their saidhinged upper ends abutting, said third section extending longitudinallybetween said upper rung of said second section and said upper rung ofsaid first section, said hooked sections of said third ladder sectionengaging with said upper rung of said first section; and said thirdsection thereby providing rungs for said upper portion of said firstsection and completing the step sequence.

3. A collapsible ladder as defined in claim 1 in which said firstplatform is horizontally disposed between said first and said secondladder sections, said first platform extending from said upper rung ofsaid first section to said upper rung of said second section, saidplatform resting on said upper rung of said second section, said secondplatform depending angularly downwardly between said upper rung of saidsecond section and the rung immediately below, thereby acting as a braceand maintaining said first and said second ladder sections at apredetermined angle; said third ladder section lying in longitudinalalignment within said second section; and two spring loaded dowels,located substantially toward the lower ends of said side rails of saidsecond section and projecting inwardly therefrom, said dowels retainingsaid hooked sections of said third ladder section thereby maintainingsaid section in longitudinal alignment within said second section.

References Cited in the file of this patent

1. A COLLAPSIBLE LADDER COMPRISING A FIRST SECTION, A SECOND SECTION, ATHIRD SECTION, A FIRST PLATFORM MEMBER AND A SECOND PLATFORM MEMBER;SAID FIRST SECTION AND SAID SECOND SECTION BEING HINGEDLY JOINED ATTHEIR UPPER ENDS; SAID FIRST SECTION INCLUDES TWO SIDE RAILS HELD INPARALLEL SPACED APART RELATIONSHIP BY A PLURALITY OF RUNGS ANDRECTANGULAR STEPS, SAID RUNGS AND SAID STEPS EXTENDING TRANSVERSELYTHEREBETWEEN AND IN PARALLEL SPACED APART RELATIONSHIP TO EACH OTHER;SAID SIDE RAILS TERMINATING IN AN UPPER SECTION HAVING NEITHER RUNGS NORSTEPS; SAID SECOND SECTION INCLUDING TWO SIDE RAILS HELD IN PARALLELSPACED APART RELATIONSHIP BY A PLURALITY OF RUNGS, SAID RUNGS EXTENDINGTRANSVERSELY THEREBETWEEN AND IN PARALLEL SPACED APART RELATIONSHIP TOEACH OTHER; A CROSS PIECE PIVOTALLY RETAINED AT ONE END THEREOF TO THEUPPER END EDGE OF ONE OF SAID SIDE RAILS OF SAID SECOND SECTION, THEOPPOSITE END OF SAID CROSS PIECE BEING LOCATED WITHIN A U HOOK, SAID UHOOK BEING RIGIDLY AFFIXED ON THE UPPER END EDGE OF THE OTHER OF SAIDSIDE RAILS OFF SAID SECOND SECTION, SAID CROSS PIECE BEING PARALLEL WITHSAID PLURALITY OF RUNGS; SAID THIRD SECTION INCLUDING TWO SIDE RAILSHELD IN PARALLEL SPACED APART RELATIONSHIP BY A PLURALITY OF RUNGS, SAIDRUNGS EXTENDING TRANSVERSELY THEREBETWEEN AND IN PARELLEL SPACED APARTRELATIONSHIP TO EACH OTHER, SAID THIRD SECTION BEING SUBSTANTIALLYSHORTER THAN EACH OF SAID FIRST AND SECOND SECTIONS; SAID THIRD SECTIONBEING PIVOTALLY RETAINED AT THE UPPER ENDS OF ITS SAID SIDE RAILS UPONAN UPPER RUNG OF SAID SECOND SECTION, THE LOWER ENDS OF SAID SIDE RAILSTERMINATING IN HOOKED SECTIONS, SAID HOOKED SECTIONS PROJECTINGLONGITUDINALLY OUTWARDLY THEREFROM, SAID SIDE RAILS